Blew a Filter this morning

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I got a T-1 (Beetle style) engine in my '69 VW microbus, but have an aftermarket remote oil filter on it. I usually use the same size filter as the T-4 (later model) engines call for as long as they have a bypass valve in the filter itself. The T-4 engines should already have a bypass in the filter mount...as far as I know they all did, anyway. My aftermarket set-up does not, of course, so I use a filter that, for sure, has a bypass valve in it so that cold, thick oil, or when there is lots of oil flow at high RPM, can temporarily go around the filter paper when it has to and get to the engine.
This is particularly important on an ACVW, as the oil pressure is regulated (more or less) by the spring piston at the end of the main oil gallery after the filter, instead of before, as on most machines. That is, of you have the second regulator at all like mine does...(1970 an on design?)
Anyway, so if the filter doesn't have a bypass in it, or a not-good-one, and the oil is too thick to go through the paper well enough, pressure downstream will be OK, but could be anything between the filter canister and the paper element.
That's what has happened to me...twice.

I have 20W-50 in the crankcase, and it's cold so I noticed the AC/Delco PF13CL was bulging and I figured the [censored] "clicker" type bypass valve isn't that good. I changed it for a NAPA ProSelect 21521 a few days ago.

This morning I was in a hurry to get something at the parts store and took off without any warm-up and half a block away my oil light comes on. I shut her down and got out to see a [censored] of oil from the filter leading all the way back to my house. The NAPA blew was bulged and blew the O-ring too! The oil pressure on the gauge was not too high, but the 20W-50 was almost like honey at 18 degrees F. I walked home and grabbed a Fram and stuck it on there. (I had oil in the Bus, but not a spare filter.) I topped it up and was fine, so far.

Now I've done all this before with 20W-50 in the cold Bus and all, but never had a filter bulge or blow out ever, on anything, in 30 years if driving.

I need to put something thinner in there for now, and keep an eye in it, sure, but I do not like the bypass in the Delco or the new design bypass on the ProSelect. I suspect them. The ProSelect now has a cheapy rubber ring that is supposed to fold inward and relieve pressure to let it down to the engine and pop back out when conditions improve. Problem is, rubber stuff gets harder in the cold. The old metal spring valve was better. It always opened at about the same pressure regardless of temperature.

The Fram I put on (forgot the number), well I'm not a fan of most Frams, but at least it has a metal spring valve bypass.

Look at these fat boys--the one on the right blew the oil:

BlowOuts.jpg
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I know that the delcos have thicker cans, good thing you caught it, im happy the motor did not seize. I'd get some thing with a heavy duty can and a proven bypass.
 
Have you really been running 20W50 in the winter? At 18 degrees morning temp?

And you're wondering why the filters are blowing?

Since the bypass for pressure is downstream of the filter, you can be sure that it receives the full pump output...which has got to be really high since, as you pointed out, 20W50 flows like honey in that temp...

You can get a stronger filter (like a Pureone) but these blown/distorted filters are symptomatic of oil that is too thick for the operating conditions...the thicker filter would merely be hiding that fact...
 
Ya. I'm thinking 5W-40 too, and a better filter. It was real dumb of my to leave the oil in after the first bulged anyway.
But I was creeping along at 20 mph when the light came on, shut off right away. No problems.
 
Originally Posted By: river_rat
Ya. I'm thinking 5W-40 too, and a better filter. It was real dumb of my to leave the oil in after the first bulged anyway.
But I was creeping along at 20 mph when the light came on, shut off right away. No problems.


I'm glad you didn't frag the engine...driving off without a warm up exacerbated the problem as the pressure rose with RPM...Just a few degrees warmer and the oil would not have developed enough pressure to blow the filter...

There are some great 5W40 HDEOs that would be much better for winter and I recognize the need for a thicker oil in an ACVW...they can get the oil pretty hot in the summer...but even in the summer heat, a good 5W40 like Rotella T6 would give you good film strength and pressure...

In all honesty, I am surprised that old girl started with 20W50 in 18 degree weather...heck, I am surprised it could even turn over...
 
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Originally Posted By: Pablo
Maybe drop down to something really thin like 15w40 in the winter.


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This is some serious filter durability testing! I'd say go thinner, but then how would we find out how much abuse a filter can take? As long as you continue paying close attention, you may as well keep on experimenting!
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I actually thought 20W-50 would have been okay at 18F. Thick, but still okay. The specs seem to suggest that it's functional down to at least 5F. Would it really be worse than 5w30 at -35F, a common situation here? Maybe that engine wouldn't even start unaided at our temps.
 
Is 20W50 recommended for 69 VW microbus? Just curious. My car with heaviest oil requirement was 89 Yugo that called for 20W40. I used 10W40 in it while it lasted (short time).
 
I get the impression you started it in the morning, after it cooled off all night long. So the thick oil built the pressure up. It's an air cooled engine isn't it? I know the climate extremes in the States are more extreme than in Germany where VWs came from. I knew a fellow with a 1964 VW bus out here who always said the engine had a hard time with heat in summer so he installed an after market oil cooler. Now I know why in winter when he would go to Big Bear he would let it idle a long time to warm it up. But in the summer that engine would cook.
 
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With oil that thick the pressure regulator was probably having a tough time regulating, which would cause higher than normal pump output pressure. I think it takes 200+ PSI to bulge a can like that.

It would be interesting to cut those filters open and see if the media is all tore up from huge PSID across the media.

When I had my first car I didn't know well enough to switch to thinner oil in the harsh winter and remember the car barley cranking over at 0 deg F with 20W-50 back in those days. Never blew a filter though ... but I can just imagine how thick and slow moving the oil was at those temperatures.
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Originally Posted By: 190E26FTW
Mobil 1 15W50 synthetic will work down to 5 degree F and maybe stop using Napa branded oil filters.



I agree. If he has to run such a thick oil in a cold climate, go synthetic.
 
As far as official recommendations for oil weight, that's a tough one, as the owner's manual mostly talks about straight weight oils available back in the day. I usually go by the 10 PSI per 1000 RPM minimum rule of thumb, but on a hot day it can't even keep up with that with 20W-50. The Magnesium case expands too much and opens up the main bearing clearances a lot. ...But I drive her hard, too. Foot in the carburetor most of the time on the highway.

The engine loves Mobil 15W-50...nice and smooth....but it leaks terribly. All those exposed push rod tubes just weep it, and then when I run the heater I get oil fumes (the heater air cones from the engine compartment}.

The OP regulator on this one is after the filter, and never got about 40 PSI on the gauge, but the gear pump was pushing it into the space between the media and canister at who know how high.

Cristobal- Yes, air-cooled, 18 degrees, no warm-up.
Something thinner is going in today or tomorrow.

I want to cut these filters and post some pictures.
 
Originally Posted By: rpn453
This is some serious filter durability testing!

I'm hardcore, man!
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River,
You have 2 pressure regulator springs and pistons on your engine if its a '70 on up block. But in either case, the 1st (and only ones on the pre-'70) are BEFORE the filter, not after. the '70 up has another spring piston at the end of the galley, and was put there to regulate the oil while the engine is at speed. The "single relief" cases has problems as they grew in displacement with oil control, hence the addition of the second relief ("dual relief case").
As for 20w-50, there is NO reason that engine should ever need that heavy a weight unless it's fogging the neighbourhood. 15w40 summer is well more than adequate, and 10w30 in winter is fine. You may also want to consider putting a relief cover on your oil pump (if there was already one there, it obviously was overwhelmed). Lots of cheap aftermarket "full flow" kits for the type 1 engines, do not have a oil pump relief cover, but just a standard cover.
 
I remember burning the paint off the oil pan of my MGA with a Hibachi one winter back in the early '70s to get it warm enough to crank over with 20W50 in it!

I had a similar filter setup on my '71 camper bus. I cannot recal what oil I rean in it... a 40 grade I think.
 
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